• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.451-459
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• 1999

Background : In sepsis, excessive generation of reactive oxygen species plays key roles in the pathogenesis of acute lung injury. The serum antioxidants such as catalase and MnSOD are elevated in sepsis and considered as predictors of acute respiratory distress syndrome(ARDS) and prognostic factors of sepsis. Peroxiredoxin(Prx) has recently been known as an unique and major intracellular antioxidant. In this study, we evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells(RAW 267.7) after treatment of oxidative stress and endotoxin and measured the amount of Prx I, Prx II and thioredoxin(Trx) in peritoneal and bronchoalveolar lavage fluid of septic animal model. Methods : Using immunoblot analysis with specific antibodies against Prx I, Prx II and Trx, we evaluated the distribution of Prx I and Prx II in human neutrophil, alveolar macrophage and red blood cell. We evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide(LPS) and measured the amount of Prx I, Prx II and Trx in peritoneal lavage fluid of intraperitoneal septic animals(septic animal model induced with intraperitoneal 6 mg/Kg LPS injection) and those in bronchoalveolar lavage fluid of intraperitoneal septic animals and intravenous septic animals(septic animal model induced with intravenous 5 mg/Kg LPS injection) and compared with the severity of lung inflammation. Results : The distribution of Prx I and Prx II were so different among human neutrophil, alveolar macrophage and red blood cell. The expression of Prx I in mouse monocyte-macrophage cells was increased after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide but that of Prx II was not increased. The amount of Prx I, Prx II and Trx were increased in peritoneal lavage fluid of intraperitoneal septic animals but were not increased in bronchoalveolar lavage fluid of intraperitoneal and intravenous septic animals regardless of the severity of lung inflammation. Conclusion : As intracellular antioxidant, the expression of Prx I is increased in mouse monocyte-macrophage cells after treatment of oxidative stress and endotoxin. The amount of Prx I, Prx II and Trx are increased in local inflammatory site but not increased in injured lung of septic animal model.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.451-459
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• 2011

Peroxiredoxins (Prxs) have a critical role in protecting cells against oxidative damage generated by reactive oxygen species (ROS). PrxI and PrxII are more than 90% homologous in their amino acid sequences, and both proteins reduce $H_2O_2$. In this study, an over-expression plasmid carrying PrxI was transfected into $PrxII^{-/-}$ mouse embryonic fibroblasts (MEFs) to investigate potential compensatory relationships between PrxI and PrxII. ROS levels induced by oxidative stress were increased in $PrxII^{-/-}$ MEFs as compared to wild-type MEFs. Moreover, exposure of $PrxII^{-/-}$ MEFs to $H_2O_2$ caused a reduction in cell viability of about 10%, and the proportion of cell death was increased compared to mock-treated $PrxII^{-/-}$ MEFs. However, transient over-expression of PrxI in $PrxII^{-/-}$ MEFs conferred increased resistance against the oxidative damage, as evidenced by increased cell viability and reduced intracellular ROS levels under $H_2O_2$ stress conditions. The findings suggest that over-expressed PrxI can partly compensate for the loss of PrxII function in PrxII-deficient MEFs.

• Tuberculosis and Respiratory Diseases
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• v.53 no.1
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• pp.36-45
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• 2002

Background : In mammals, the activity of antioxidant enzymes is increased in adult lung to adapt to hyperoxia. The increase of these activities is augmented in neonates and is known as an important mechanism of tolerance to high oxygen levels. Peroxiredoxin(Prx) is an abundant and ubiquitous intracellular antioxidant enzyme. Prx I and II are major cytosolic subtypes. The aim of this study was to examine th Prx I and II mRNA and protein expression levels in adult rat lungs and to compare then with those of neonatal rat lungs exposed to hyperoxia. Materials and Methods : Adult Sprague-Dawley rats and neonates that were delivered from timed pregnant Sprague-Dawley rat were randomly exposed to normoxia or hyperoxia. After exposure to high oxygen level for a set time, the bronchoalveolar lavage fluid and lung tissue were obtained. The Prx I and II protein expression levels were measured by western blot analysis using polyclonal rabbit anti-Prx I or anti-Prx II antibodies and the relative expression of the Prx I and Prx II per Actin protein were obtained as an internal standard. The Prx I and II mRNA expression levels were measured by northernblot analysis using Prx I and Prx II-specific cDNA prepared from pCRPrx I and pCRPrx II, and the relative Prx I and Prx II expression levels per Actin mRNA were obtained as an internal standard. Results : Hyperoxia induced some peak increase in the Prx I mRNA levels after 24 hour in adult rats. Interestingly, hyperoxia induced a marked increase of Prx I mRNA 24 hour in neonatal rats. However, hyperoxia did not induce an alteration in the expression of Prx II mRNA in both the adult and neonatal rat lungs. Hyperoxia did not induce an alteration in the expression of the Prx I and Prx II protein in both the adult and neonatal rat lungs. Hyperoxia did not induce an alteration in the amount of Prx I and Prx II protein all the times in the bronchoalveolar fluid of adult rats. Conclusion : Prx I and II is differently regulated by hyperoxia in adult and neonatal rat lung at the transcriptional level. The prominent upregulation of Prx I mRNA in neonates compared to those in adults by hyperoxia may be another mechanism of resistance to high oxygen levels in neonate.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.272-279
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• 2006

$\underline{Purpose}$: This study investigated the influence of irradiation and cisplatin on PrxI & PrxII expression and on their survival rates (SR) in SK-N-BE2C and Rat2 cell lines. $\underline{Materials\;and\;Methods}$: The amount of PrxI & PrxII production with or without N-acetyl-L-cysteine (NAC) pretreatment was studied using a western blot after 20 Gy irradiation to determine the degree of inhibition of ROS accumulation. In addition, the amount of PrxI & PrxII production after cisplatin and after combination with cisplatin and 20 Gy irradiation was studied. The SRs of the cell lines in SK-N-BE2C and Rat 2 cells, applied with 20 Gy irradiation only, with various concentrations of cisplatin and with the combination of both, were studied. The 20 Gy irradiation-only group and the combination group were each subdivided according to NAC pretreatment, and corresponding SRs were observed at 2, 6, 12 and 48 hours after treatment. $\underline{Results}$: Compared with the control group, the amount of PrxI in SK-N-BE2C increased up to 60 minutes after irradiation and slightly increased after irradiation with NAC pretreatment 60 minutes. It did not increase in Rat2 after irradiation regardless of NAC pretreatment. PrxII in SK-N-BE2C and Rat2 was not increased after irradiation regardless of NAC pretreatment. The amounts of PrxI and PrxII in SK-N-BE2C and Rat2 were not increased either with the cisplatin-only treatment or the combination treatment with cisplatin and irradiation. SRs of irradiation group with or without NAC pretreatment and the combination group with or without NAC pretreatment were compared with each other in SK-N-BE2C and Rat2. SR was significantly high for the group with increased amount of PrxI, NAC pretreatment and lower the cisplatin concentration. SR of the group in SK-N-BE2C which had irradiation with NAC pretreatment tended to be slightly higher than the group who had irradiation without NAC pretreatment. SR of the group in Rat2 which had irradiation with NAC pretreatment was significantly higher than that the group which had irradiation without NAC pretreatment. Compared to the combination group, the irradiation-only group revealed statistically significant SR decrease with the maximal difference at 12 hours. However, at 48 hours the SR of the combination group was significantly lower than the irradiation-only group. $\underline{Conclusion}$: PrxI is suggested to be an antioxidant enzyme because the amount of PrxI was increased by irradiation but decreased pretreatment NAC, a known antioxidants. Furthermore, cisplatin may inhibit PrxI production which may lead to increase cytotoxicity of irradiation. The expression of PrxI may play an important role in cytotoxicity mechanism caused by irradiation and cisplatin.

• BMB Reports
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• v.50 no.8
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• pp.391-392
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• 2017

Overexpression of mammalian 2-Cys peroxiredoxin (Prx) enzymes is observed in most cancer tissues. Nevertheless, their specific roles in colorectal cancer (CRC) progression has yet to be fully elucidated. Here, a novel molecular mechanism by which PrxII/Tankyrase (TNKS) interaction mediates survival of adenomatous polyposis coli (APC)-mutant CRC cells was explored. In mice with an inactivating APC mutation, a model of spontaneous intestinal tumorigenesis, deletion of PrxII reduced intestinal adenomatous polyposis and thereby increased survival. In APC-mutant human CRC cells, PrxII depletion hindered PARP-dependent Axin1 degradation through TNKS inactivation. $H_2O_2-sensitive$ Cys residues in the zinc-binding domain of TNKS1 was found to be crucial for PARsylation activity. Mechanistically, direct binding of PrxII to ARC4/5 domains of TNKS conferred vital redox protection against oxidative inactivation. As a proof-of-concept experiment, a chemical compound targeting PrxII inhibited the growth of tumors xenografted with APC-mutation-positive CRC cells. Collectively, the results provide evidence revealing a novel redox mechanism for regulating TNKS activity such that physical interaction between PrxII and TNKS promoted survival of APC-mutant colorectal cancer cells by PrxII-dependent antioxidant shielding.

• BMB Reports
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• v.45 no.10
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• pp.560-564
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• 2012

The role of peroxiredoxin (Prx) I as an erythrocyte antioxidant defense in red blood cells (RBCs) is controversial. Here we investigated the function of Prx I by using Prx $I^{-/-}$ and Prx I/$II^{-/-}$ mice. Prx $I^{-/-}$ mice exhibited a normal blood profile. However, Prx I/$II^{-/-}$ mice showed more significantly increased Heinz body formation as compared with Prx $II^{-/-}$ mice. The clearance rate of Heinz body-containing RBCs in Prx $I^{-/-}$ mice decreased significantly through the treatment of aniline hydrochloride (AH) compared with wild-type mice. Prx I deficiency decreased the phagocytic capacity of macrophage in clearing Heinz body-containing RBCs. Our data demonstrate that Prx I deficiency did not cause hemolytic anemia, but showed that further increased hemolytic anemia symptoms in Prx $II^{-/-}$ mice by attenuating phagocytic capacity of macrophage in oxidative stress damaged RBCs, suggesting a novel role of Prx I in phagocytosis of macrophage.

• Tuberculosis and Respiratory Diseases
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• v.59 no.2
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• pp.142-150
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• 2005

Background : Continuous growth stimulation by various factors, as well as chronic oxidative stress, may co-exist in many solid tumors, such as lung cancer. A new family of antioxidant proteins, the peroxiredoxins (Prxs), have been implicated in the regulation of many cellular processes, including cell proliferation, differentiation and apoptosis. However, a real pathophysiological significance of Prx proteins, especially in lung disease, has not been sufficiently defined. Therefore, this study was conducted to investigate the distribution and expression of various Prx isoforms in lung cancer and other pulmonary conditions. Method : Patients diagnosed with lung cancer, and who underwent surgery at the Ajou Medical Center, were enrolled. The expressions of Prxs, Thioredoxin (Trx) and Thioredoxin reductase (TR) were analyzed using proteomic techniques and the subcellular localization of Prx proteins was studied using immunohistochemistry on normal mouse lung tissue. Result : Immunohistochemical staining has shown the isoforms of Prx I, II, III and V are predominantly expressed in bronchial and alveolar lining epithelia, as well as in the alveolar macrophages of the normal mouse lung. The isoforms of Prx I and III, and thioredoxin were also found to be over-expressed in the lung cancer tissues compared to their paired normal lung controls. There was also an increased amount of the oxidized form of Prx I, as well as a putative truncated form of Prx III, in the lung cancer samples when analyzed using 2-dimensional electrophoresis. In addition, a 43 kDa intermediate molecular weight protein band, and other high molecular weight bands of over 20 kDa, recognized by the anti-Prx I antibody, were present in the tissue extracts of lung cancer patients on 1-Dimensional electrophoresis, which require further investigation. Conclusion : The over-expressions of Prx I and III, and Trx in human lung cancer tissue, as well as their possible chaperoning function, may represent an attempt by tumor cells to adjust to their microenvironment in a manner advantageous to their survival and proliferation, while maintaining their malignant potential.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.296-303
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• 2010

A peroxiredoxin cDNA (PgPrx) was isolated and characterized from the leaves of Panax ginseng. The cDNA is 716 nucleotides long and has an open reading frame of 489 base pairs with a deduced amino acid sequence of 162 residues. The calculated molecular mass of the mature protein is approximately 17.4 kDa with a predicted isoelectric point of 5.37. A GenBank BlastX search revealed that the deduced amino acid sequence of PgPrx shares a high degree homology with type II peroxiredoxin (Prx) proteins in other plants. The PgPrx gene was highly expressed in leaves, and expressed at a low level in the stem. To analyze the gene expression of PgPrx in response to various abiotic stresses, we utilized real-time quantitative RT-PCR. Our results reveal that PgPrx expression is induced by ultraviolet irradiation, low temperature, and salt. The induction of PgPrx in response to abiotic stimuli suggests that ginseng Prx may function to protect the host against environmental stresses.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.71-77
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• 2001

This experiment was designed to improve the production efficiency of germ-line chimeric mice from phospholipase C (PLC)-$\beta$3 or peroxiredoxin (Prx) E -targeted ($\Delta$) ES cells by the investigating the manipulation conditions and characteristics of Jl ES cells. Four targeting clones were isolated to investigate the karyotypical and morphological stability prior to injection. All clones ($\Delta$PLC$\beta$-3 C3, $\Delta$Prx II C3, C10 and I5) showed more than 80% euploidism, however, most of $\Delta$PLC$\beta$-3 C3 clones were extensively differentiated compared to the other clones. Nine of 13 $\Delta$Prx II chimeras appeared to have at least 80% chimerism, whereas $\Delta$PLC$\beta$-3 C3 chimeras had 20% chimerism at most. Therefore, the morphological stability of ES cells under stable euploidism might mainly affect the production rate of high-coat chimeric mice. To increase the collection rate of injectable blastocysts (IBs), 5 to 10 week -aged C57BL/6J female mice were sacrificed at 3.5 days post-coitum. Ten week-aged mice were the most optimal IB donors by showing the highest collection rate (2.94/mouse) of injectable blastocysts without increase of non-injectable embryos (0.29/mouse). Foster mothers might be another factor because ICR x C57BL/6J F1 foster mother showed more increased productivity in litter size (2.8 vs. 5.6) and chimera (0 vs. 35.3%) than those of ICR foster mothers. In conclusion, the efficient production of germ-line chimeras mainly depends on the maintenance of ES cell morphology during targeting procedure, and the establishment of manipulation conditions might be a key point to maximize it.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.40-64
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• 2005

Much biochemical information on peroxiredoxins (Prxs) has been reported but a genuine physiological function for these proteins has not been established. We show here that two cytosolic yeast Prxs, cPrxI and II, exist in a variety of forms that differ in their structure and molecular weight (MW) and that they can act both as a peroxidase and as a molecular chaperone. The peroxidase function predominates in the lower MW proteins, whereas the chaperone function is more significant in the higher MW complexes. Oxidative stress and heat shock exposure of yeasts causesthe protein structures of cPrxI and II to shift from low MW species to high MW complexes. This triggers a peroxidase-to-chaperone functional switch. These in vivo changes are primarily guided by the active peroxidase site residue, $Cys^{47}$, which serves as an efficient $'H_2O_2-sensor'$ in the cells. The chaperone function of the proteins enhances yeast resistance to heat shock.